Shuttle construction for shoe sewing machines



17, 1954 c. N. LESTAKIS SHUTTLE CONSTRUCTION FQR SHOE SEWING MACHINES Filed May 21, 1951 2 Sheets-Sheet l Med/a r Aug. 17, 1954 Filed May 21, 1951 C. N. LESTAKIS SHUTTLE CONSTRUCTION FOR SHOE sswm MACHINES 2 Sheets-Sheet 2 Patented Aug. 17, 1954 UNITED STATES PATENT oFFicE SHUTTLE CONSTRUCTION FOR SHOE SEWING MACHINES Christy N. Lestakis, Minneapolis, Minn. Application May 21, 1951, Serial No. 227,382

4 Claims. 1

My invention relates to lock stitch sewing machines and particularly to those employing the curved hook needle and rotary shuttle provided with a hook or beak adapted to pick up the needle loop on one side of the bobbin and release it on the opposite side thereof whereby to form the lock stitch in conjunction with the thread coming from the bobbin.

The principal objective of the invention is to increase the thread-carrying capacity of the bobbin.

Because of the limited space imposed by design and working requirements the capacity of bobbins in present machines is very limited. As an. operator of shoe repair machinery I. have found this limited bobbin capacity very disadvantageous and very exasperating at times for it seems that the thread is always running out and at the most inopportune time.

In the Landis type of machine the bobbin is concentrically mounted in the bobbin carrier but the bobbin carrier is eceentrically mounted in the shuttle whose housing has an annular groove or guideway for the reception of an annular rib which encompasses the shuttle and the beak thereon used to pick up the needle:- loop and transfer it from one side of the bobbin to the other.

The beak must naturally be in. position to dothis very thing as must the needle and the loop spreader which co-operate to form and spread the loop so that the beak may enter it- Sufficient clearance for the shoe to be: worked upon must be had while the above elements and the means for driving them function.

In the Landis type machine this has all been worked out in a very eflicient and practical manner but the largest bobbin possible is only 1 in diameter and thick. This machine provides a clearance of from the top of the Work support to the bottom of the beak on the shuttle when said beak is in its lowest position.

It is quite apparent that in this: type of machine any increase in the diameter of the bobbin will automatically call for an increase in the beak circle which prevents the beak from 0.0-

operating with the needle and the loop spreaden.

and automatically causes the beak to encroach upon the necessary work space.

I have been able not only to hold the work space but to increase the bobbin to 2 in diameter and make it thicker without disturbing the needle or the loop spreader and their operating mechanisms.

How the above has been accomplished is. illus- 2. trated inthe accompanying drawings and described in that portion of the specification which. follows:

Fig. 1 of the drawings is a front elevation of the shuttle arrangement; Fig. 2 is an elevation showing the needle loop spread ready to be entered by the beak; Fig. 3' is an elevation and section on the line 3'---3 of the bobbin elevation; Fig. 4' isan elevation and section on the line i -4 of the bobbin carrier elevation; Fig. 5 is an elevation and section on the line 5-5 of the shuttle elevation; Fig. 6 is a section on the line 6-6 of Fig. 1; Fig. 7 is an elevation of the shutthe driving dog which is shown partly in section in Fig. 6; Fig. 8 is an elevation of the needle thread diagram; Fig. 9 shows the shuttle beak from the front.

In general the mechanism in which we are. interested includes a bobbin l, a bobbin case or carrier 2-; a shuttle 3 a driving dog for the shut tie 3, a housing 5 within which the shuttle 3 is rotatable, and gearing 6 to rotate the dog 4 forward and back.

The bobbin I, shownin Fig. 3, comprises a hollow hub portion 1 upon which are" mounted two spaced apart circular disks 8 for the reception of the bobbin thread 9 (not shown) therebetween.

The hollow hub t of the bobbin l is rotatable upon a. stud tit which projects from the interior surface of the end closure wall it of the cylindrical bobbin carrier 2 shown in Fig. 4 From the exterior surface of. this end wall It proj'ects a thread guide l2 whose exterior surface is blended into the surface of said end wall H to provide the least obstruction to the passage: of the, thread, forming the needle loop [3, over the surface of the bobbin carrier 2. has av hole M therein inv communication with the interior of the bobbin carrier thru which thebobbin thread 9 may be withdrawn. In communication with this hole [4 is a groove l5 formed in. the exterior surface of the guide t2 so that; the bobbin thread 9 may remain below the surface of the guide While being withdrawn and hence. out of contact with the thread of the'need'le loop I 3: as it moves over the surface of the bobbin carrier The center of the circular recess R in. the shuttle 3 for the reception of the bobbin carrier 2 is positioned A to the left and above the V shuttle center.

The bobbin carrier 2 is an easy fit Within'this circular recess R formed in said shuttle 3 and is mounted therein with its end wall l-I facing out- The guide 12' jects beyond the open end of the shuttle 3 as shown in Fig. 6, leaving a space S between said end wall H and the retaining plate IE for the passage of the thread of the needle loop |3. In operative position the space S is in approximate vertical alignment with the thread hole W in the work for the reception of the thread 9 coming from the bobbin. See Figs. 2, 4, 6, and 9.

The shuttle 3 is cylindrical in form with its end wall is faced inwardly and provided with an opening ISA therein into which the stud It of the bobbin carrier 2 projects. The cylindrical wall I!) of the shuttle 3 may be described as having considerable thickness from the exterior surface of which is removed a ring sector portion 2|! of approximately 90 degrees, said sector portion beginning adjacent the forward edge of the hook or beak 2| which projects outwardly from the cylindrical wall portion l9 of the shuttle 3 beyond a flange thereon.

The outwardly facing end, or open end, of the shuttle cylindrical or ring wall I9 is formed with an outwardly extending flange 22, with its outer corner rounded off, extending over approximately 225 degrees of the perimeter of the said ring wall I9. The housing 5 within which the shuttle 3 is rotatable back and forth is recessed for the reception of said shuttle 3 and the driving dog 4 therefor. This recessed portion 23 of the housing 5 is counterbored for the reception of the flange 22 and to form a shoulder 24 against which the interior face of the the flange 22 may seat and be guided. A retaining ring 25 is secured to the rim 26 of the housing 5 by the screws 21 and serves to form with the counterbore 28 a groove or guideway 29 for the reception and retention of the flange 22 on the shuttle 3.

The shuttle a is loosely confined within the housing 5 and within the curvature of the driving dog 4 formed to occupy the major portion of the ring sector portion 20 missing from the cylindrical wall I3 of the shuttle 3. See Fig. 1. This driving dog 4 has the form of a ring sector portion or annular sector and extends from the face of the disk 3!] mounted on the shaft 3| jour nailed in the bearing 32 in the housing 5. See Fig. 6. A bevel pinion 33 is mounted on the shaft 3| and in turn is driven by a gear sector (not, shown) as is common practice in such machines.

In this type of stitching machine the hook 34A on the needle 34 picks up the thread of the needle loop l3 and carries said loop |3 upwardly until it is engaged by the loop spreader 35 whose movement is such as to widen the top of the loop l3 so that the beak 2| on the shuttle 3 may readily enter said loop |3 and as it continues up and around on its circular path lift said loop |3 off the needle 34 and the loop spreader 35 which at the same instant drops down and out of said loop.

The side 2|A of the beak 2| is positioned approximately the mid line of the shuttle 3 on its open side and drops straight back or parallel to the flange 22 to just beyond the first crook 36 in its top face and then flares toward the shuttle side. On the opposite side the beak flares back to the shuttle side. The beak 2| also flares downwardly to and merges into the shuttle wall |9--all curves being smooth so that the loop I3 may readily slide over the shuttle. Another crook 31 is formed adjacent the juncture of the beak 2| and the cylindrical wall IQ of the shuttle 3. The crook 33 is so positioned as to receive the loop |3 at the instant the loop spreader 35 has reached its uppermost and outermost position shown in Figs. 1 and 2. The loop |3 is carried in the crock 36 of the beak 2| upwardly until eventually it slides down into the crook 31 which carries the loop 13 over the shuttle 3 until it reaches a point approximately diametrically opposite the point it was received by the crook 36 when it is no longer retained in the crook 31 and is free to drop down and out between the dog 4 and the shuttle 3 since the shuttle 3 is free to float between the radial ends 20A of the annular sector portion 2|? which has greater circumferential length than the dog 4. This dog 4 has its corner 4A snipped off to make more sure the guidance of the loop toward the shuttle.

The recessed portion 23 of the housing 5 is faced off to form a guiding surface 33 for the straight face 21A of the beak 2| and. its end Wall 5A is turned to have a sliding contact with the outer circumferential edge 33 of the beak 2|, whereby the shuttle is securely held and guided within its housing regardless of the portion of the flange 22 removed. Fig. 6, shows the contact made by the straight portion or face 2 IA with the portions 33 and 39 of the housing 5. This has been shown dotted for clearness since the beak would not ordinarily show in section in this figure.

Fig. 1, shows the shoe line 40 common to the mechanism of the Landis type of machine and to the machine described herein. In other words both machines have a clearance of /2 between this work line 40 and the point 4| of the shuttle beak. While maintaining the clearance the needle 34 and the loop spreader 35 can still co-cperate with the beak 2| on the shuttle 3. Several minor adjustments must be made since the center of the shuttle 3 has been raised slightly. Holding these vital points my mechanism permits an increase of bobbin capacity of approximately 300 per cent.

Fig. 8, shows the threading diagram of the Landis type of machine to which my invention is particularly adaptable. Since my bobbin is larger in diameter than the one used in this machine more thread must be pulled. This extra thread may be had by changing the length of the arm 42.

It is apparent that many changes of design may be made without departing from the basic idea and I do not limit my invention to the exact form illustrated but extend it to all that comes fairly within the scope of the appended claims.

What I claim as new is:

1. A shoe stitching machine having a shuttle formed as a cylinder with an open end having an outwardly extending flange occupying a portion of the rim of said open end and a beak extending from the cylindrical Wall beyond said flange perimeter having a straight face portion parallel to said flange, and a shuttle housing receiving the shuttle therewithin, said shuttle housing having an inwardly extending rib with spaced parallel guiding surfaces on parallel to the straight face portion of the shuttle beak and the other receiving the outwardly extending shuttle flange to guide the shuttle during rotation thereof within the housing.

2. The structure set forth in claim 1 but wherein the shuttle housing is also formed With a portion to engage the peripheral end of the shuttle beak.

3. In a shoe stitching machine in combination, a cylindrical shuttle formed with an open end provided with an outstanding guide flange on a portion of the rim of said open end and a beak extending from the shuttle body between the flange ends to beyond the flange perimeter having a straight face portion parallel to the shuttle flange, and a shuttle housing having portions guiding the shuttle during rotation within said housing comprising a rib extending inwardly between the shuttle flange and the straight face portion of the shuttle beak and a portion in engagement with the peripheral end of said beak.

4. In a shoe stitching machine shuttle the combination of, a cylindrical body portion having a circular bobbin carrier recess in one end thereof positioned to form a thickened wall portion having a ring sector portion removed therefrom to form a space for the reception of shuttle driving means between the end Walls formed by the removal of the ring sector portion from the body portion, an outstanding guide flange occupying the major portion of the cylindrical body rim, and a beak extending from the thickened wall portion to beyond the flange perimeter, said beak having a straight face guide portion facing the flange end of the shuttle and extending from the beak end to approximately midway the length of said beak and positioned approximately midway the shuttle length.

reeferences Cited in the file of this patent UNITED STATES PATENTS Number Name Date 529,064 Denne Nov. 13, 1894 620,729 Bertrand Mar. '7, 1899 1,098,874 Ballard June 2, 1914 1,895,257 Minett Jan. 24, 1933 2,219,308 Haas Oct. 29, 1940 

